Generally, surgeries and trauma cause wound bleeding resulting in blood loss, and thus hemostasis is needed immediately. Surgeons also need to seal the wounds caused by surgical procedures, so as to prevent the wounds from re-bleeding and infection.
Hemostatic products commonly used for treating wounds can be classified in the following categories:                1. Hemostatic dressing including bandages, hemostatic sponges and gauzes and the like;        2. Hemostatic film or hemostatic glue;        3. Hemostatic powder.        
Hemostatic products (e.g., the hemostatic materials used during surgical procedure) applied to the inside of tissues and organs of body are normally those materials that can be degraded by enzymes or engulfed by phagocytes in the human body. Therefore, the hemostatic products can be degraded or metabolized after applying hemostatic products for a certain time period.
Hemostatic products applied onto the body surface or surfaces of a body cavity (orifice) (e.g., upper respiratory tract, digestive tract, genital tract etc.) are normally those materials that are not necessarily required to be degraded by enzymes or engulfed by phagocytes in human body. These hemostatic products can be removed or peeled off with the scar after applying for a certain time period, and then discharged out of the body.
Polyoxyethylene (PEO) is also known as polyethylene oxide. It is a commonly used medical polymer and often used as an excipient or a plasticizer suitable for the medicaments in manufacturing medical binders or tablets. The structural unit of PEO is —[CH2CH2O]—, and the molecular weight of PEO varies in a wide range. PEO with a relative molecular weight ranging from 200 to 20,000 Daltons is a viscous liquid or waxy solid. PEO with a relative molecular weight ranging from 1×105 to 1×106 Daltons is a white, flowable powder.
The molecular weight of a synthetic polymer typically has polydispersity. In a general sense, the molecular weight of polymer refers to an average molecular weight. Depending on the methods for statistics of average molecular weight, the average molecular weight of polymer can be further defined as number-average molecular weight, weight-average molecular weight, Z-average molecular weight and viscosity-average molecular weight. Among them, the viscosity-average molecular weight refers to molar weight of polymer, which is measured using viscosity method. In various polymers, linear polymers have high solution viscosity and the viscosity value has a correlation with molecular weight, therefore, the molecular weight of linear polymers is typically measured using the viscosity method. Moreover, devices used in the viscosity method are simple, easy for operation, suitable for a wide range of molecular weights and can achieve high accuracy. Measuring viscosity-average molecular weight by using the viscosity method is a common experimental technology for one having ordinary skill in the polymer field (see, for example, LI Jinsong et al., “Measurement for Viscosity-average Molecular Weight of Polyethylene Oxide Wax”, SHANDONG CHEMISTRY, Vol. 35, 2006; YUAN Jinying, et al., “Measurement for Viscosity-average Molecular Weight of Polyethylene Glycol”, POLYMER MATERIALS AND ENGINEERING, Vol. 15, No. 4, 1999).
Hemostatic bandages and gauzes commonly used to stop bleeding, protect wounds, avoiding re-bleeding and infection are based on the principle of compression by bandaging. Recently, it has been reported that natural hemostatic polysaccharide (e.g., chitosan, cellulose and the like) and synthetic polymer materials are coated on the surface of a fabric dressing after being dissolved in liquid, so as to form hemostatic adhesive bandages for hemostasis. For example, Chinese patent application CN86103931 discloses an adhesive bandage, which consists of a backing coated with pressure-sensitive adhesive, an absorbent pad fixed on the backing, and a perforated plastic film wound release cover overlaid on the absorbent pad, wherein a coating comprising polyethylene oxide having a molecular weight of at least 600,000 Daltons is provided on the wound release cover. The bandage disclosed in this Chinese patent application comprises polyethylene oxide with a low molecular weight, and use of this hemostatic product in the form of bandage has some deficiencies, for example, such bandage cannot be used for a bleeding wound surface within body or body cavity orifice (e.g., interior surface of digestive tract).
Additionally, hemostatic glue (e.g., hydrogel and sealant glue) prepared with polysaccharide or synthetic polymer can be applied topically on the sutured skin wound or wound on the body surface caused by trauma for the purpose of protecting the wound, avoiding exudation of fluid and preventing infection. Such hemostatic glue is readily used for the wound on the body surface, but cannot be applied on the bleeding wound surface within the body cavity (e.g., interior surface of digestive tract).
So far, there has been no report about applying PEO powders topically on internal wounds for the purpose of hemostasis and wound sealing.
Therefore, there is a need for a hemostatic product which is convenient for use, has excellent efficacy on both hemostasis and wound sealing. It can be applied topically on a wound surface or a bleeding wound surface within the body cavity orifice via ancillary devices, such as specific delivery device for administration by virtues of endoscope, so as to achieve rapidly hemostasis, form polymer-blood glue matrix, seal the wound and avoid re-bleeding.